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there is overwhelming evidence to support the use ofHSG `T" soils for all reclaimed areas, and in fact the use of HSG B actually constitutes a conservative assumption. As discussed below, a strong case can be made for selecting HSG A, although that is not proposed here. Referring to Section 630.0701 of the National Engineering Handbook, each HSG is described, and the final sentence of each soil group description provides a minimum infiltration rate. Specifically for deep soils such as regraded spoils covered with topsoil, Hydrologic Soil Group A has a minimum infiltration rate of 1.42 in/hr, Hydrologic Soil Group B has a minimum infiltration rate of0.57in/hr, Hydrologic Soil Group Chas a minimum infiltration rate of 0.06112/12r, and Hydrologic Soil Group D has an infiltration rate of less than that. Finally, the results presented in the 1981 Striffler and Rhodes study clearly indicate that regardless of the mine location, the infiltration rates observed are well beyond those normally assigned to a HSG C soil. Although Colowyo's data is limited to 6 sites which would have had an undisturbed mapped soil with HSG C, the infiltration rate observed in the field tests was well beyond a Type C soil. In fact it appears more like a HSG A soil. The average measured infiltration rate was 5.5 cm/hr (2.2 inches/hr; Table 10 in Striffler and Rhodes). Figure 2 presents a plot of the average infiltration on all 14 sites in that study. These are described in Tables A -1 through A -14 of the Striffler and Rhodes report. There are 76 field infiltration tests altogether represented on Figure 2. Figure 2 is for illustration purposes only and is not intended to be part of the TR -95 revision. Eleven of the sites are clearly HSG B orA soils. Only two of the sites approach a HSG Csoil. CCC never intended to use Striffler and Rhodes to extrapolate between different mines or different regions, but the results of all of the tests clearly indicate the infiltration rate of reclaimed lands is better represented as HSG A or B. In Colowyo's case, the measured infiltration rates suggest HSG A, with infiltration rates over 2 inches/hr. In the review comment above, it is stated that past studies and studies at other sites do not provide justification for altering curve number values. On the contrary, due to the preponderance of high infiltration rates at all reclaimed sites, the exact opposite is true. • Additional information would provide better rationale for altering the CN values. This could include site specific infiltration tests and/or calibration of existing models using rainfall and runoff data.